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24781 is a prime number

24781 has 2 divisors, whose sum is σ = 24782. Its totient is φ = 24780.

The previous prime is 24767. The next prime is 24793. The reversal of 24781 is 18742.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19881 + 4900 = 141^2 + 70^2 .

It is a cyclic number.

It is not a de Polignac number, because 24781 - 25 = 24749 is a prime.

It is a super-2 number, since 2×247812 = 1228195922, which contains 22 as substring.

It is a nialpdrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (24181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12390 + 12391.

It is an arithmetic number, because the mean of its divisors is an integer number (12391).

224781 is an apocalyptic number.

It is an amenable number.

24781 is a deficient number, since it is larger than the sum of its proper divisors (1).

24781 is an equidigital number, since it uses as much as digits as its factorization.

24781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 448, while the sum is 22.

The square root of 24781 is about 157.4198208613. The cubic root of 24781 is about 29.1545455303.

The spelling of 24781 in words is "twenty-four thousand, seven hundred eighty-one".